ACTIVATION
المؤلف:
John Field
المصدر:
Psycholinguistics
الجزء والصفحة:
P5
2025-07-22
612
ACTIVATION
An important metaphor in models of language processing, based on the way information is transmitted within the brain by electrical impulses. It is often employed in theories of lexical access. A word in the lexicon is said to be activated to the extent that evidence supports it. Thus, reading the sequence fro- would activate FROG, FROM, FRONT, FROST etc. for a reader. The items would not all be activated to the same degree: some (e.g. FROM) start off with an advantage (or perhaps a lower recognition threshold) because they are more frequent. If the next letter the reader encounters is g, this new information boosts the activation of FROG to a point where it ‘fires’: i.e. the word on the page is regarded as successfully matched to the item FROG in the reader’s lexicon. At this point, the activation of the other words (known as competitors) begins to decay.
In many models of language processing (especially connectionist ones) activation is represented as feeding up through different levels of analysis. It is assumed that there is a sub-letter level of processing that deals with letter features (parts of letters). If the reader sees a vertical line, the result will be to feed excitatory (or facilitatory) activation upwards to the letter level, supporting the likelihood of the capital letters E, F, H etc. No activation (or negative inhibitory activation) is lent to C, S or X, which do not conform at all to what has been seen. If the next feature processed is three horizontal lines, then E will be boosted to the point where recognition occurs and will win out over F and H. In some models, there is inhibitory activation between competitors at the same level. As E clearly becomes the correct candidate, the result is to depress the activation of F and H.
A phenomenon known as spreading activation provides an account of the way words are connected in the lexicon. When the word FOOT is read or heard, it lends activation to a string of other words which are associated with it, making them easier to recognise. They might be associated by form (in reading: FOOT– food, fool) or they might be semantically associated (FOOT– hand, toe, leg). Activation is said to vary in relation to the strength of the connections.
Thus, the connection between FOOT and hand would be stronger than that between FOOT and elbow.
Note that these effects are automatic: they are not under our voluntary control, so we cannot turn them on or off. In this, they are different from context effects.
See also: Association, Competition, Connectionism, Lexical access, Lexical storage, Priming effect, Spreading activation
الاكثر قراءة في Linguistics fields
اخر الاخبار
اخبار العتبة العباسية المقدسة
